1. Field of the Invention
The present invention relates to an image forming apparatus having a blank sheet ejection preventing function and a blank sheet ejection preventing method.
2. Description of the Related Art
In recent years and continuing, digital color multi function peripherals (MFP) including functions such as a copying function, a facsimile (FAX) function, a printing function, a scanning function, and a function for delivering input images, are becoming indispensable at offices. An MFP is often provided with a device for automatically feeding originals referred to as an ADF (Auto Document Feeder), so that a plural number of originals can be scanned at once. The user can efficiently make copies of originals with this function.
Conventionally, when a blank original is included in the batch of originals, the blank original is printed out as a blank copy, which leads to a waste in transfer sheets. In an attempt to address this problem, patent document 1 discloses a determining unit for determining not to perform an image forming (printing) operation for a blank original. In the invention disclosed in patent document 1, image information is scanned from an original, and when it is determined that the original is a blank sheet, the image forming operation is cancelled or a warning is indicated to the user, so that transfer sheets are prevented from being wasted.
Patent Document 1: Japanese Laid-Open Patent Application No. 2000-201254
However, in recent years and continuing, there are cases where an electronic file of a material created at a user's terminal is directly sent to an MFP, and the electronic file is printed out with the MFP. However, the invention disclosed in patent document 1 is for optically scanning an original and determining whether the scanned original is a blank sheet. Therefore, if a blank file is printed out from the user's terminal via the network, a blank transfer sheet cannot be prevented from being output. In this case, transfer sheets are wasted.